Adirondack chairs are a larger type of chair and are very popular. For many years, these chairs were made of wood with the pieces of the chair nailed, glued, bolted, or screwed together to form a single unit. The chair has a straight back that is formed by multiple wooden planks that extend from a seat at an angle. Most wooden Adirondack chairs are not foldable. They are heavy and also very difficult to stack. More recently, some Adirondack chairs have been made of plastic. These chairs are molded to look like the old wooden Adirondack chairs.
U.S. Pat. No. 7,401,854 to Adams discloses foldable Adirondack chairs. The chairs may be stacked on top of each other by folding the rear legs to a position substantially parallel to the seat and subsequently positioning nesting the chair within a second chair. Unfortunately, this method of stacking Adirondack chairs can provide a stack of chairs that is not straight. Often, the stack of Adirondack chairs disclosed in U.S. Pat. No. 7,401,854 has a forward lean, which can cause the stack of chairs to fall down.
U.S. Pat. No. 8,333,430 B2 to Adams et al. discloses a molded plastic Adirondack chair having a lumbar support. This Adirondack chair is stackable as shown in FIG. 9 of the patent. These Adirondack chairs are stacked on pallets for shipment to a retailer. The retailer may display the chairs on their shipping pallets. A 52 foot long trailer can carry 1368 of these Adirondack chairs stacked on pallets. Adams Mfg. Corp. has made a commercial version of this Adirondack chair from a blend of polypropylene and polypropylene containing a small amount of polyethylene to provide impact resistance that weighs around 7 pounds. An Adirondack chair made with a variation on this formulation that contains about 8% calcium filler weighs around 7.5 pounds. Other molded plastic Adirondack chairs in the marketplace weight 10.23 and 11.27 pounds. There is a need for a lighter weight Adirondack chair that would allow more chairs to be stacked per pallet and more chairs carried per trailer. The cost to make such a lightweight chair could be significantly less than the cost to make the molded plastic Adirondack chairs that are now available in the marketplace.
Plastic chairs for outdoor use must meet certain standard performance requirements or retailers will not purchase them. ASTM F 1561-03 standard sets forth specific tests to be performed in order to determine if a plastic chair meets those requirements. One test involves placing the chair on a glass surface which simulates smooth surfaces such as linoleum and wet pool decks. Three hundred pounds is placed on the chair. The chair must then hold for at least 30 minutes without failing. Failure occurs when the chair collapses or when any visible evidence of structural damage develops such as cracking. Another test from the ANSI/BIFMA X5.1 standard involves dropping a 225 pound canvas bag containing lead shot in tightly packed compartments on the chair. The bag is dropped from a height of 6 inches at a location on the seat which is not more than ½ inch from the back. The chair is then checked for cracks.
Prior to the present invention the art has not created an Adirondack chair weighing less than 7 pounds that will meet both of these performance requirements.